marketwatch.com: Tiger Woods DUI: Prescription drugs are a growing threat to safety on American roads

Tiger Woods isn’t the only one driving under the influence of prescription drugs.

Woods, the former No. 1 golfer in the world, was arrested early Monday near his home on Jupiter Island, Fla., for driving under the influence. Police reportedly found him asleep at the steering wheel of a running vehicle and arrested him because of his slurred speech and for failing police-instructed roadside tasks. But his alcohol breath test was zero. In a statement late Monday, Woods said, “I take full responsibility for my actions. I want the public to know that alcohol was not involved. What happened was an unexpected reaction to prescribed medications.” Woods had back surgery last month.

Crashes involving drugged drivers have nearly doubled over the last decade. In 2015, 21% of the 32,166 fatal crashes in the U.S. involved one driver who tested positive for drugs, up from 12% of the 39,252 fatal crashes in 2005, according to the National Highway Traffic Safety Administration, according to data released last year by the government’s National Highway Traffic Safety Administration. “Use of marijuana and prescription drugs is increasingly prominent among drivers on America’s roads, which raises a new safety challenge,” the NHTSA says. “While it’s illegal across the United States to drive while drunk, the laws involving drugged driving vary across the states.”

Video footage released online showed former “Dynasty” star Linda Evans, 74, being arrested in 2014 in Washington State for a DUI after driving erratically. “Unfortunately, I believe that you are under the influence,” the police officer told the actress. She was given a ticket for DUI in the footage first released last March, but this was later amended to reckless driving. Police found 30 pink pills in her car, which Evans said she used as muscle relaxers. “It’s true I was driving while being in physical pain,” Evans told People magazine, but I was not impaired by any narcotic. I did not take any opiate or alcohol.” (Her management did not immediately reply to a request for comment.)

Marijuana is another problem for road safety. Fatal crashes involving drivers who recently used marijuana doubled in Washington State to 17% in 2014 from 8% in 2013 after the legalization of the drug there, according to a study released last year by the AAA Foundation for Traffic Safety. Legal limits for marijuana and driving are arbitrary and unsupported by science, “which could result in unsafe motorists going free and others being wrongfully convicted for impaired driving,” AAA spokeswoman Tamra Johnson said. Recreational sales of marijuana ballooned 80% to $1.8 billion in 2016, according to data from Marijuana Business Daily.

Another recent survey by the NHTSA found that marijuana users are more likely to be involved in accidents, which may be due to the legalization of marijuana in many states, but that the increased risk may be due in part because they are more likely to be in groups at higher risk of crashes. “In particular, marijuana users are more likely to be young men — a group already at high risk,” the study found. While fatal traffic accidents have declined gradually over the last 10 to 15 years helped by stricter laws related to drunk driving and public safety awareness campaigns, it has crept back up over the last year amid other concerns related to texting while driving.

The spike in fatalities involving drugged drivers is likely an indication of the wider problem. The rate of drug overdose deaths in the U.S. in 2015, adjusted for age, was more than 2.5 times the rate in 1999, according to recent data released by the Centers for Disease Control and Prevention, due to a fall in the price of heroin and accessibility to prescription drugs. The rate of drug overdose deaths increased to 16.3 per 100,000 in 2015 from 6.1 per 100,000 people in 1999, an average rise of 5.5% a year. The biggest spike in fatal drug overdoses took place among Generation X and baby boomers, the CDC concluded.

Some states have created legal limits, also known as “per se limits,” which specify the maximum amount of active tetrahydrocannabinol or THC that drivers can have in their system based on a blood test. THC is the main chemical component in marijuana that can impair driver performance and affect the mind, and the presence of active THC is generally suggestive of recent marijuana use. These limits are similar in concept to the 0.08% blood alcohol limit for driving under the influence of alcohol. But DUIs do run the gamut from marijuana and alcohol to muscle relaxers and prescription pain killers, especially if it leads to impaired driving.

DUIs laws for alcohol also vary by state. Arizona is one of the strictest states for DUIs and has the longest minimum jail term (10 days) for first-time offenders, a vehicle impound and a 90-day minimum jail time for a second offense; DUI is an automatic felony with a third offense and an ignition interlock device is mandatory after one DUI conviction. South Dakota is the least strict out of all 50 states, as it has no minimum sentence for either a first or second DUI; although a third DUI is considered a felony in that state, there is no administrative license suspension, no vehicle impound, no administrative license suspension and no mandatory ignition interlock device required.